Pro Handyman Blog

Anti-Siphon Valve Insulation

It may not be tonight, but it's coming. That time of year when we get a short period of freezing temperatures. Its good for business but a real headache for homeowners. Which brings me to the topic of today's post. Insulate your exposed exterior piping. The most common occurrence in a freeze is that the piping and/or pressure vacuum breaker (or anti-siphon valve) freezes and splits open. The piping is typically PVC and the pressure vacuum breaker (PVB) is brass. As water freezes it expands...and the strength of this is phenomenal. Freezing water will easily split brass or copper piping. You have to try to keep them warm.

Manufacturers make heat tape which is plugged into an electrical outlet that warms up and protects the piping. With heat tape though you can't wrap it on itself, it can only make contact with the pipe.

In my climate, I use typical pipe insulation to protect the pipes and the pressure vacuum breaker. You can open the insulation up and cover various areas on the PVB and then tape everything together.

You can also buy covers that are made of a Styrofoam material and then place this directly over the PVB assembly.

In a pinch, you can drape the entire assembly with a towel and then cover that with a plastic garbage bag. The towel will help keep the cold off of the assembly and the plastic garbage bag will keep it dry (and prevent it from freezing) if it rains. This makes for cheap but effective anti-siphon valve insulation.